Cylindrical tank construction



Jam. 31, 1939. R. c. HANSEN CYLTNDRICAL TANK CONSTRUCTION Filed Feb. 2, 1937 Ray C. Hansen INV TOR ATTORNEY Patented Jan. 31, 1939 UNITED STAB.

Ray C. Hansen, Portland, Greg, assignor to M &

(30., Portland, Green, a cor- M Wood Working poraticn of Oregon Application February 2, 1937, Serial No. 123,621

2 Claims.

This invention relates to improvements in the construction of tanks manufactured of wood staves and designed primarily for storing acid solutions.

5 Tanks of this character are used extensively by the pulp and paper industries, though not exclusively, for the storage of water, pulp and sulphurous and other acids used in the manufacture of pulp and paper. Prior to applicants l discovery such tanks were constructed of staves of equal breadth and thickness, each stave being of a length equal to the height of the tank to avoid crevices between abutting staves. In tanks from 50,000 to 100,000 gallons capacity, the staves l commonly measured 6" x 6" or 8" x 8" and from 16 to 40 feet in length, according to the size of the tank, and were sawed as required to complete tanks on order. Under favorable conditions, two-months time was consumed in fabri- 20 eating the material required for the construction of a single tank. Another diificulty has been that timbers of the size previously used cannot be thoroughly kiln-dried, and the completed tank often has required repairs due to shrinking and checking of the staves.

Applicant has discovered that such tanks may successfully be constructed of staves of lesser dimensions and of convenient lengths, which may be kiln-dried to approximately 6% to 10% moisture content before fabrication of the tank. Applicant utilizes relatively thin staves, the thickness of the tank wall being the same as in former constructions, the difference being that in the present construction the staves are approximately one-half or less of the former width, and are made up of variable lengths, as may be convenient. Because of the use for which these tanks are intended, it is necessary to seal the crevices between abutting staves and to prevent the sealing material from being dissipated by action of the acid within the tank. This is accomplished in applicants construction by the use of spaced splines set into transverse grooves in the ends of the abutting staves, the splines being so positioned as to act as retainers for cementing material placed therebetween. An important advantage of this construction is that the time now required to manufacture a tank embodying applicants invention is approximately ten days, the necessary sizes of lumber commonly stocked by lumber dealers.

It is, therefore, an object of the present invention to generally improve and simplify the con struction of cylindrical tanks, by reason of which the tank may be manufactured and made ready for shipment in much less time than heretofore has been found necessary to build such tanks, and with a considerable saving in the cost of materials used therein.

A. further object of the invention is to pro- '5 vide: a manner of constructing cylindrical acid tanks whereby relatively narrow staves of any convenient lengths may be used, which staves may be kilndried to avoid shrinking or checking after fabrication of the tank.

A further object of the invention is to provide, in cylindrical tank construction, for the application of cementing material to abutting stave ends and for protecting said material from the action of acids contained within the tank.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the construction, combination and arrangement of parts hereinafter described, illustrated in the accompanying draw- 20 ing, and sought to be defined in the appended claims; it being understood that various changes in form, proportion, size and details of construction within the scope of the claims may be resorted to without departing from the spirit or 25 sacrificing any of the advantages of the invention.

In the drawing:

Figure l is a perspective elevation of a portion of a cylindrical tank constructed to embody my invention.

Figure 2 illustrates the spline and groove construction employed in effecting a seal between abutting stave ends.

Figure 3 illustrates the manner in which cementing material is applied to abutting stave ends 35 between the splines.

Figure 4 is a sectional elevation of the spline and groove construction taken edgewise of the stave as on the line 4-4 of Figure 2.

Figure 5 is a perspective elevation of one of 4 the staves, showing the spaced grooves for reception of the splines.

Referring now to the drawing, the tank is composed of a circular wall I, a top or head 2, and a floor or bottom 3. The encircling hoops or 45 bands 4 are of the ordinary kind commonly employed in the construction of cylindrical tanks, and are adjustable by the use of any of the ordinary devices for that purpose now in common use. Each stave is provided with a croze 50 for receiving the bottom, and also with a croze for receiving the head. Each stave is made with a groove 5 in one side thereof and a bead or tongue 6 on the other side. This tongue and groove construction serves the particular function of cen- 55 tering the staves to facilitate setting up the tank at the place of use. As noted in Figure 5, the staves are slightly beveled to correspond with the radius of the tank to be constructed so that the parts may easily be assembled into a circular wall.

In an embodiment of the construction which is the subject matter of the present invention, the tank is constructed of staves 1 which may be sawed from available timbers, irrespective of length. Staves which are shorter than the tank wall are used in end to end abutment with other short staves to form a wall of the desired height. Each of the short staves is formed with transverse spaced grooves 88 in its end, the grooves in abutting staves being in vertical alignment. A metal spline 9 is inserted in aligned grooves to hold the staves in alignment and to form a seal, and the sealing is perfected by the use of a creosote or asphalt preparation applied to the abutting ends of the staves immediately before assembling the tank. While the entire end surface of each stave is painted or coated with the cementing material, it has been found to be advantageous to place an added amount of the material, as at Ill, on the stave ends intermediate the spaced splines. 99 before forcing the stave ends together. When the staves are then forced into position the soft material I0 is forced into all available crevices between abutting and adjoining staves, and into the grooves 88 around the splines 9-9 to effect an absolute seal. The spaced splines 9-9 serve to prevent dissipation or wearing away of the cementing material therebetween, either by the action of the acids contained within the tank, or by the action of the elements on the outside of the tank. The splines may be made of antimonial lead or of other alloid metals according to the properties required to withstand the particular acids to be stored in the tank.

Referring to Figure 1, it will be noted that the head and bottom of the tank are likewise constructed of staves of varying lengths, and that the crevices between abutting staves are sealed in the same manner as has been described in connection with the tank wall. In assembling the tank the staves are so arranged that the joints between abutting staves will be staggered, and that at no point in either the wall or the end closures will a joint extend through more than one stave.

It is not intended to limit the application of the present invention to the particular form of construction and arrangement of parts in a tank as illustrated, and the form of construction and arrangement of parts herein shown and described is to be considered as suggestive only. For example, the construction may take the form of a semi-circular structure employing horizontally disposed staves, as illustrated in Letters Patent No. 502,474, issued August 1, 1893 to Guy Sterling. I deem myself entitled to all such uses of the invention, either in its entirety or in part, as may be included within the spirit and scope of the appended claims.

Having now described my invention and in what manner the same may be used, What I claim as new and desire to protect by Letters Patent is:

1. In tank construction, a plurality of staves arranged in end to end abutting relation, the contiguous ends of abutting staves being formed with spaced aligned grooves cut transversely of said staves, a spline for each of said grooves, the Width of each spline being equal to the Width of the staves, the splines being designed to extend from edge to edge of the staves, and a cementing material applied to the ends of abutting staves intermediate said splines to form an impermeable seal therebetween.

2. In wood stave tank construction in which the tank is composed of wood staves of varying lengths, means for sealing the crevices between the ends of abutting staves and for preventing dissipation of the seal by the action of liquid within the tank and the elements exteriorly of the tank, said means comprising splines set into spaced aligned grooves in the ends of abutting staves parallel to the inner and outer faces thereof, the width of each said spline being commensurate with the width of the staves, and a cementing material applied to the abutting ends of the staves between said splines.

RAY C. HANSEN. 

